Stock meter



March 14, 1961 J. E. FOOTE ETAL STOCK METER Filed Sept. 15, 1959 M8 mm wN QC 0E w w m 5 M s K C 3 E w. H. mv a? f l 9 0w 5. m mm 8 C M mm m MWN.? I A u I mw K I Y B |||l N I g I mm ()0- mm m.

ATTORNEY United States Patent STOCK METER Filed Sept. 15, 1959, Ser. No.840,054

8 Claims. (Cl. 222-356) This invention relates to stock meters, and moreparticularly to apparatus for dispensing metered quantities of liquidstock. Although apparatus embodying the invention is capable ofdispensing and metering various types of liquid stock, it isparticularly applicable for supplying liquid pulp slurry to pulp moldingmachines, especially for pulp stock of high consistency, wherein arelatively high ratio of pulp fibers to liquid is present therein.

Stock meters are customarily employed for regulating the rate at whichpulp slurry stock is supplied to pulp molding machines, since it isdesirable to supply the stock at a rate of flow commensurate with therate of production of the molding machines. Usually, such meters havecomprised gate valves or suitable throttling devices mounted in thestock supply pipes, and sometimes such meters have involved relativelymovable, slidably interfitting elements. When pulp stock of highconsistency was metered in such devices, difficulty was frequentlyencountered with a tendency of the devices to become clogged bydeposited pulp fibers. In contrast with the free-flowing characteristicsof highly dilute pulp stock, which may contain only about 1% to 2% byweight of pulp fibers, pulp stock of relatively high consistency, whichmay contain as much as about 5% by weight of pulp fibers, exhibits anatural tendency to deposit pulp fibers in conglomerate mounds about anyrestrictive openings through which the stock must flow. Particularly inthe case of metering devices having relatively movable, slidablyinterfitting parts, the pulp fibers deposited from high consistencystock sometimes cause jamming of the stock meter, and consequentshutdown of the entire pulp molding machine.

An object of the present invention is to provide a new and improvedstock meter.

' Another object of the invention is to provide a new and improveddevice for dispensing and metering liquid stock.

Still another object of the invention is to provide a new and improvedstock meter for supplying pulp slurry stock to pulp molding machines.

Yet another object of the invention is to provide a new and improvedstock meter for supplying liquid pulp stock of relatively highconsistency to pulp molding machines, which meter is constructed withoutrelatively movable, slidably interfitting elements in contact with thestock, to avoid the danger of jamming such parts by deposited pulpfibers.

' Other objects and the nature and advantages of the instant inventionwill be apparent from the following detailed description, taken inconjunction with the accompanying drawings, wherein:

Fig. 1 is a vertical sectional viewof a stock meter embodying theinvention, shown at one stage of its operation; and

- Fig. 2 is a view corresponding to Fig. 1, showing the stock meter atanother stage of its operation.

In accordance with the present invention, the stock meter illustrated inthe drawings includes a generally ice rectangular reservoir 10 adaptedto contain a substantial quantity of pulp slurry stock of relativelyhigh consistency, which may comprise a homogeneous suspension of atleast about 5% by weight of pulp fibers in water. The reser voir 10 mayhave an open top portion 12, and it is provided with aninlet stocksupply pipe 14, which may be mounted at one side thereof and submergedbelow the upper level of the stock contained therein. The pulp stock ismaintained within the reservoir 19 at a predetermined constant leveltherein controlled by a vertically adjustable darn or weir 16 mounted atone side of the reservoir 10 adjacent to an overflow compartment 18,which is attached to the reservoir 10 near its upper portion 12. Pulpstock is constantly pumped into the reservoir 10 through the inlet pipe14 from a suitable source of supply (not shown),

and any more stock than is needed to maintain the predetermined constantlevel Within the reservoir 10 overflows the weir 16 into the overflowcompartment 18, from which it is drained away through an overflow pipe20 and returned to said source of supply.

A tubular measuring receptacle 22, which is preferably cylindrical inconfiguration, is disposed vertically and movably mounted centrallywithin the reservoir 10 for vertical reciprocation therein. Thereceptacle 22 is provided with an open upper end 24 secured to asemicircular bail 26, which is connected to a vertical piston rod 28extending downwardly from a piston head 3% mounted on the top portion 12of the reservoir ill. The piston rod. 28 is vertically slidable througha guide plate 32 mounted within a bracket 34 which supports the pistonhead 30 on the top portion 12 of the reservoir 10. Verticalreciprocation of the receptacle 22 by actuation of the piston head 30causes the open upper end 24 of this receptacle to be moved alternatelybetween an emerged position and submerged position, with respect to thepredetermined constant level of the pulp stock maintained within thereservoir 10. In this manner the receptacle 22 is allowed to becomefilled with the pulp stock during each downstroke of its reciprocalmovement.

The tubular measuring cylinder 22 is also provided with an open bottomend 36 terminating in an annular beveled valve seat 38, which is adaptedto cooperate with a resiliently mounted, vertically movable valve 41)POSl: tioned directly therebelow. The valve 40 is mounted Within adischarge chamber 42, which is relatively smaller than the reservoir 10and is secured centrally to the bottom thereof, so as to be directlyunderneath the vertically movable measuring receptacle 22. An annular,flexible, liquid-impervious diaphragm 44, preferably composed of naturalor synthetic rubber, is secured to and extends between the open lowerend 36 of the receptacle 22 and a surrounding horizontal bottom wallportion 46 of the reservoir 10. The diaphragm 44 in effect constitutes acontinuation of the bottom wall 46 of the reservoir 10, and thediaphragm is provided with a central aperture 45 through which the lowerend 36 of the receptacle 22 projects, so that this diaphragm forms aliquid-tight sealed partition between the reservoir 1t? and thedischarge compartment 42.

An important feature of the present invention is the fact that theflexible diaphragm 44 constantly maintains a liquid-tight seal betweenthe reservoir 10 and the discharge chamber 42 during the entirereciprocatory movement of the measuring receptacle 22, and thisconstruction avoids reliance upon slidably interfitting, relativelymovable parts, which would have an attendant undesirable tendency tobecome jammed by deposited pulp fibers when stock of high consistency isbeing metered. Thus, if the vertically reciprocable receptacle 22 merelyprojected through a rigid aperture in the bottom wall 46 of thereservoir 10, or if a pair of telescopically slidable tubes were used inplace of the valve seat 38 and the valve 41), then the hazardof havingsuch jamming of the relatively movable parts by deposited pulp fiberswould inevitably be present.

The valve 40 is mounted on the upper end of a verti c'ally disposed andmovable valve stem 48, which projects through a central aperture 49 inthe bottom wall of the discharge compartment 42. An adjustable stop nut50 is mounted in threaded engagement with the stem 48 for longitudinalmovement therealong to limit the extent of vertical movement of thevalve stem 48 and a helical compression spring 52 surrounding the stem48 extends between the valve 40 and the bottom wall of the dischargecompartment 42, thereby normally urging the valve 40 upwardly to themaximum extent permitted by engagement of the nut 50 with the sides ofthe aperture 49 in the bottom of the discharge chamber 42. An annularskirt 54 extends downwardly from the outer periphery of the valve 40 andfits telescopically in sliding engagement over an annular flange 56which projects upwardly from the aperture 49 in the bottom of thedischarge chamber 42. The skirt 54 and the flange 56 together constitutea housing concentrically surrounding the valve stem 48, and theyfunction as a guide for the vertical reciprocatory movement of the valve40. The telescopically interfitting skirt 54 and flange 56 are kept outof contact with the liquid pulp stock to prevent them from becomingjammed by any pulp fibers deposited from the stock, by means of a secondannular flexible diaphragm 54 which is secured to and extends betweenthe skirt 54 and the bottom of the discharge chamber 42, so as tomaintain a liquid-tight partition therebetween. A discharge pipe 60 isprovided at one side of the bottom of the discharge chamber 42 forcommunication with a pulp molding machine (not shown) being providedwith a controlled quantity of pulp stock by the stock meter.

Operation In operation, actuation of the piston head 30 causes thetubular measuring cylinder 22 to be reciprocated vertically alternatelybetween its elevated emerged position, shown in Fig. l, and its loweredsubmerged position, shown in Fig. 2. In its fully elevated position, themeasuring receptacle 22 is empty, being open at both its upper end 24and its lower end 36. On the downstroke of its reciprocatory movement,the receptacle 22 is moved downwardly until its upper end 24 issubmerged below the constant predetermined level of liquid pulp stockwithin the reservoir 19, which level is maintained by constantly pumpingfresh pulp stock into the reservoir through the inlet pipe 14 andallowing any excess stock to overflow the vertically adjustable darn orweir 16 into the overflow compartment 123. Just before the receptacle 22becomes submerged in the liquid pulp stock, the annular beveled valveseat 38 on the open lower end 36 of this receptacle is brought intoliquid-sealing contact with the resiliently mounted valve 4!). Continueddownward movement of the receptacle 22 carries the valve 49 downwardlyto the limit ofthe stroke of the piston head 3%, or until the downwardmovement of the valve 49 is stopped by engagement thereof with theannular flange 56 projecting upwardly from the bottom of the dischargechamber 42. in its one lowermost submerged position, the receptacle 22becomes filled with the liquid pulp stock by allowing the stock to flowfreely into the open upper end 24 of the receptacle While its lower end36 is closed by the valve 40.

On the upstroke of the cylindrical measuring receptacle 22, which is nowfilled with liquid pulp stock, just after the upper end 24 of thereceptacle 22 emerges above the constant upper level of the pulp stockin the reservoir 10, the lower end 36 of the receptacle 22 is opened bymovement of the valve 49 away from the valve seat 38, thereby allowingthe contents of the receptacle 22 to flow downwardly into the dischargechamber 42 and thence outwardly through the discharge pipe 60 to thepulp molding machine (not shown) being supplied with liquid pulp stockby the stock meter. At the beginning of the upstroke of the receptacle22, the valve 40 moves along with it under the urging of the helicalcompression spring 52, and thus keeps the lower end 36 of the receptacle22 closed during the initial portion of its upward movement. Upwardmovement of the valve 40 continues until the adjustable stop nut 50 iscarried upwardly by the valve stem 43 into engagement with the sides ofthe aperture 49 in bottom of the discharge chamber 42, which actionhalts the upward movement of the valve 4%. As the receptacle 22continues the upward stroke of its reciprocatory movement while thevalve 45} is thus prevented from continuing to travel upwardly alongtherewith, the valve seat 38 thereby becomes separated from the valve40, and thus opens the lower end 36 of the receptacle 22.

Repetition of the above described cycle of operations by continuedvertical reciprocation of the tubular receptacle 22 supplies the pulpmolding machine with a succession of measured quantities of liquid pulpstock, each of which quantities is equivalent to the internal volume ofthe measuring receptacle 22. Preferabl the piston head 39 is actuated intimed relationship to the operation of the pulp molding machine tosupply said machine with a controlled quantity of pulp stockcommensurate with the production rate of the machine.

It is particularly important to observe that the annular flexiblediaphragm 44 constantly maintains a liquid-tight sealed partitionbetween the reservoir 10 and the discharge chamber 42 during the entirereciprocatory movement of the cylindrical measuring receptacle 22, Theflexibility of the diaphragm 44 enables its inner edge to move with thereciprocating receptacle 22, while its outer edge remains anchored tothe bottom wall 45 of the reservoir 10. Likewise, the flexible diaphragm58 has one of its edges secured immovably to the bottom of the dischargechamber 42, while the other edge of the diaphragm 58 is joined to andmovable with the skirt 54 extending downwardly from the valve 40. Theseflexible diaphragms advantageously prevent the liquid pulp stock fromcontacting any slidably interfitting apparatus elements, which mightbecome jammed by pulp fibers deposited from the stock, especially fromstock of high consistency. Stock meters embodying the present inventionare capable of operating efliciently the pulp stock of rela tively highconsistency, which may containas much as about 5% by weight of pulpfibers, without the necessity of periodically shutting down theapparatus to clean out jammed movable elements.

Although only a single embodiment of the invention has been illustratedand described, it will be obvious to those skilled in the art thatvarious changes may be made without departing from the spirit and scopeof the invention, and therefore the invention is not limited to what isshown in the drawings and described in the specification, but only asindicated in the appended claims.

What is claimed is:

V 1. A stock meter, comprising a reservoir adapted to contain liquidstock, means for maintaining the stock at a predetermined level withinthe reservoir, atubular measuring receptacle mounted movably within thereservoir and having normally open upper and lower ends, means forvertically reciprocating the receptacle alternately between an emergedposition in which its open upper end is elevated above the level of theliquid stock in the reservoir and a submerged position in which said endis lowered below the level of the stock, a discharge chamber mountedbelow the receptacle for receiving the liquid stock therefrom, a valvecooperating with the open lower end of the receptacle for closing saidend when thereceptacle is in its submerged position and, opening saidend when the receptacle is in its emerged position, and a flexiblepartition secured to both the receptacle and the reservior and vextending between the reservoir and the discharge chamher, saidpartition flexing during reciprocation of the receptacle and to maintaina liquid tight seal between the reservior and the discharge chamber.

2. The stock meter defined by claim 1, wherein the partition is aflexible, liquid-impervious diaphragm secared to and extending betweenthe lower end of the receptacle and the bottom of the reservior.

3. A stock meter, comprising a reservoir adapted to contain liquidstock, means for maintaining the stock at a predetermined level withinthe reservoir, a tubular measuring receptacle having normally open upperand lower ends disposed vertically within the reservoir and reciprocablevertically therein, means for vertically reciprocating the receptaclealternately between an emerged position in which its open upper end iselevated above the level of the liquid stock in the reservior and asubmerged position in which said end is lowered below the level of thestock, a discharge chamber mounted below the receptacle for receivingthe liquid stock therefrom, a valve mounted movably within the dischargechamber below the open lower end of the receptacle, said valve closingthe open lower end of the receptacle when the receptacle is in itssubmerged position and opening said end when the receptacle is in itsemerged position, and a flexible diaphragm forming a liquid-tightpartition between the reservoir and the discharge chamber, saiddiaphragm having an aperture through which the lower end of thereceptacle projects into the chamber and to which said end is secured sothat said diaphragm is flexed during the vertical reciprocation of thereceptacle.

4. The stock meter defined by claim 3, wherein the valve is reciprocablevertically, and it is normally urged upwardly toward the receptacle by acompression spring mounted in the bottom of the discharge chamber.

5. The stock meter defined by claim 3, wherein the valve is secured tothe upper end of a vertical stem mounted movably in the dischargechamber and reciprocable vertically for movement with the measuringreceptacle during a portion of its reciprocatory movement, an adjustablestop is mounted on the stem for limiting the movement of the stem, and aspring mounted on the stem urges the value upwardly toward thereceptacle.

6. The stock meter defined by claim 5, wherein said stem and spring arehoused within an annular flange projecting upwardly from the bottom ofthe discharge chamber, an annular skirt depending from the valve fitstelescopically in sliding engagement over said flange, and a secondflexible diaphragm forms a liquid-tight partition between said skirt andthe bottom of the discharge chamber.

7. A stock meter for supplying measured quantifies of liquid pulp slurrystock to pulp molding machines, comprising a reservoir adapted tocontain liquid pulp stock, means for maintaining the stock at apredetermined constant level within the reservoir, a tubular measuringreceptacle having normally open upper and lower ends disposed verticallywithin the reservoir and reciprocable vertically therein, a pistonsecured to the receptacle for vertically reciprocating it alternatelybetween an emerged position in which its open upper end is elevatedabove the level of the pulp stock in the reservoir and a submergedposition in which said end is lowered below the level of. the stock, adischarge chamber secured to the reservoir directly below the receptaclefor receiving measured quantities of the stock therefrom, a flexiblediaphragm forming a liquid tight partition between the reservoir and thedischarge chamber, said diaphragm having an aperture through which thelower end of the receptacle projects into the chamber and to which saidend is secured so that said diaphragm is flexed during verticalreciprocation of the receptacle, a vertically movable valve mountedresiliently within the discharge chamber directly below the open lowerend of the receptacle and movable therewith during a portion of itsreciprocatory movement, said valve closing the I open lower end of thereceptacle when the receptacle is in its lowered submerged position andopening said end when the receptacle is in its elevated emergedposition, a telescopically movable guide extending between the valve andthe bottom of the discharge chamber for controlling the movement :of thevalve, and a second flexible diaphragm forming a liquid-tight partitionbetween said guide and the bottom of the discharge chamber.

8. The stock meter defined by claim 7, wherein the telescopicallymovable guide comprises an angular flange projecting upwardly from thebottom of the discharge chamber, and an annular skirt extendingdownwardly from the valve fits telescopically in sliding engagement oversaid flange, said second flexible diaphragm having an aperture intowhich the lower end of said skirt fits in liquid-tight engagement toform a liquid-tight partition between said guide and the bottom of thedischarge chamber.

References Cited in the file of this patent UNITED STATES PATENTS2,534,997 Smith Dec. 19, 1950

